Method of and apparatus for forming a composite tubular support



April 24, 1956- MOGRANN METHOD OF AND APPARATUS FOR FORMING A COMPOSITE TUBULAR SUPPORT 3 Sheets-Sheet 1 Filed NOV. 18, 1949 Inventor: 650/955 64 Mai/64mm @wmez )/OM wi h,

U ited statfis P t METHOD on AND'APPARATUS For; oRMING A COMPOSITE: TUBULAR surronr G'Or'geA. McGi'ann, Gary, Ind., assignpr States Steel Corporatre ja c'orporati'on of fNew Jersey Application November- 18, 1949, Serial No. 128,224 8 Claims. on 153-70 such members have been formed by drawing the same through. dies which is a slow andexpensive operation. Itis an object of the present invention to provide a method and apparatus for efficiently-and cheaply corrugating tubular supporting members.

The foregoing and further objects will be apparent from the .followingspecification when read in conjunction with the attacheddrawing, wherein: V

Figure I is a longitudinal section of my improved support;

Figure; 2--is a cross sectionofline 11-11 of Figure 1; and

Figures 3 through 7 are cross sections of roll passes embodying the teachings of my invention.

Referring more particularly to the drawings, the letter S indicates a tubular supporting member composed of an outer pipe 2 and a tubular reenforcing or insert member 4 disposed interiorly of the base portion of the pipe 2. It will be noted that the pipe 2 has flutes or corrugations 6 extending longitudinally throughout the length thereof and that the supporting member 4 is similarly fluted so that the intermediate surfaces of the two members are in close, tight engagement throughout the whole extent thereof. As a result of such engagement, the insert member provides maximum stiffness to the assembly since it is impossible to produce a sliding action therebetween. As a matter of fact, the two members cannot be separated without destroying one or the other, or both.

The foregoing fiuting is accomplished by cold rolling telescoped tubular members in the specially designed roll passes of my invention. The roll passes are disposed in longitudinally aligned stands as indicated by the numeral 10, the pairs of rolls 12 in the alternate stands being disposed at 90 relative to the rolls in the intermediate stands. This is the generally conventional arrangement in so-called sinking or sinking-sizing mills and has accordingly not been shown in the drawings. However, the passes and contours of the rolls forming the same have novel features enabling the conjoint longitudinal fluting,

' which will be more fully explained hereinafter.

In the present arrangement, six stands or passes are preferred and Figures 3 to 7, inclusive, of the drawings are vertical sections thereof showing the contours of the rolls. As is indicated by the foregoing figures, the rolls have their axes of rotation disposed normal to the pass line. Each of the pairs of rolls 12 have complementary hollowed-out grooved portions 14 which define a rolling pass. It is noted that each of the rolls has a fluted portion 18 composed of flutes 16 onboth sides of the and adjacent its center line cc thereof. Preferably this portion extends for between about 45" to 60 or 1 e ach side of the center line confining the flutingto arcs qf ljf to 60 on each side of the center line thus preventing an undercut condition which occursif the who .11.8100 14 is fluted. Moreover, it restricts the flutmg action the most eifective'forniing portion of the rolls, "llu'rs to the alternate 90 disposition f the'fqlls, the s 911g and fourth roll passes flute or work the portion of e workpiece not acted on by the rolls in ents; andth rd passes. Thefiftl-iandsixth passes ar e roundi'ngjip passes and only do suflicient reducing of the composite me1 nher to insurethe correct shapethereof,

An examination of the drawings also d the rolls are contoured so that crests 17' of times formed at the mid-portionoftlie rolls in the rst second passes, and these crests. are then alternately sposed at the edges of the two rolls in the succeedingpasSe's'. This enables better control of the rolling passesby insuring evenly distributed application of the rollingp res. Further, the crests disposed at the edges of th s, which are rounded or radiused, tendto guide the world piece and prevent any twisting thereof. I

Another feature of the roll passes of my design, especially adapting them to the cold fluting of tubular inertia bers, is that the passes are slightly oval in shape 7 That; is, the distance d-d acrossthe width of the grooves is slightly greater than the combined depths along the c te if line thereof; plus the clearance e.e betveen the Preferably the width should exceed the combinedd and clearance an amount equal to between. 2 a of the combined depth and clearance. 'It willbe ap t h P s on oivy li ath ,fi ing a pe i a greater squ'eeze' therein than would be p v v ifthe passes were of generally circular cross section. This extra squeezing action is particularly desirable in that it compensates for the tendency of the cold rolled metal to 1 1 member comprising telescoping a pair of tubular members and passing said telescoped tubular members through a plurality of grooved roll passes, the rolls forming said passes having their working mid-portions fluted, the rolls in the stands being disposed normal to the pass line and each of said stands being disposed at a ninety degree angle relative to the adjacent stands.

2. The method of forming a composite tubularsupport member comprising telescoping a pair of tubular members and passing said tubular members while at substantially room temperature through a plurality of roll passes formed of pairs of grooved rolls, the rolls forming said passes having their mid-portions fluted, the rolls in the stands being disposed normal to the pass line and each of said stands being disposed at right angles relative to the adjacent stands, the width of the combined grooves in said pairs of rolls exceeding the depth thereof.

3. Apparatus for longitudinally corrugating steel tubular members by cold rolling comprising, a plurality of oppositelydisposed pairs of grooved rolls forming aligned substantially enclosed working passes, the said rolls having their axes of rotation disposed normal to the pass line thereof and the axes of the successive pairs of rolls being disposed at right angles relative to the adjacent rolls on either side thereof, each of said rolls being fluted adjacent the mid-portion thereof, the width of the grooved rolling pass formed by said rolls exceeding the depth thereof.

4. Apparatus for longitudinally corrugating steel tubular members by cold rolling comprising, a plurality of oppositely disposed pairs of grooved rolls forming aligned substantially enclosed working passes, the said rolls having their axes disposed normal to the pass line thereof and the axes of the successive pairs of rolls being disposed at right angles relative to the adjacent rolls on either side thereof, each of said rolls being fluted between 45 and 60 from each side of its center line and the width of the grooved rolling pass formed by each pair of said rolls exceeding the depth thereof.

5. Apparatus for longitudinally corrugating steel tubular members by cold rolling comprising, a plurality of oppositely disposed pairs of grooved rolls forming aligned substantially enclosed working passes, the said rolls having their axes of rotation disposed normal to the pass line thereof and the axes of the successive pairs of rolls being disposed at right angles relative to the adjacent rolls on either side thereof, each of said rolls being fluted between 45 and 60 from each side of its center line, the width of the grooved rolling pass formed by each pair of said rolls exceeding the depth thereof by an amount between 2 and 5%.

6. Apparatus for longitudinally corrugating steel tubular members by cold rolling comprising, a plurality of oppositely disposed pairs of grooved rolls forming aligned substantially enclosed working passes, the said rolls having their axes of rotation disposed normal to the pass line thereof and the axes of the successive pairs of rolls being disposed at right angles relative to the adjacent rolls on either side thereof, each of said rolls being fluted adjacent the mid-portion thereof, the width of the grooved rolling pass formed by each pair of said rolls exceeding the depth thereof by an amount between 2 and 5%.

7. The method of forming a composite tubular support member comprising telescoping a pair of tubular members and passing said telescoped tubular members through at least two grooved roll passes, the rolls forming said passes having their working mid-portions fluted, the telescoped tubular members being fluted on opposite sides thereof in the first of said passes and in the second pass fluted on opposite sides thereof intermediate the flutes formed in the first pass.

8. The method of forming a composite tubular support member comprising telescoping a pair of tubular members and passing said telescoped tubular members while at cold working temperatures through at least two grooved roll passes, the rolls forming said passes being fluted between and from each side of their center lines, the width of the grooved rolling pass formed by said rolls exceeding the depth thereof by an amount between 2 and 5%, the telescoped tubular members being fluted on opposite sides thereof in the first of said passes and in the second pass fluted on opposite sides thereof intermediate the flutes formed in the first pass.

References Cited in the file of this patent UNITED STATES PATENTS 686,816 Macphail Nov. 19, 1901 888,114 Numan May 19, 1908 888,984 Fell May 26, 1908 1,023,119 Barrick Apr. 16, 1912 1,033,569 Fell July 23, 1912 1,691,134 Schlaich Nov. 13, 1928 1,779,185 Meiser et al Oct. 21, 1930 1,877,583 Pfatf Sept. 13, 1932 1,963,057 Wilcox June 12, 1934 2,205,893 Unger June 25, 1940 2,442,850 Glesmann June 8, 1948 FOREIGN PATENTS 95,041 Sweden Mar. 15, 1939 

